U.S. Pat. No. 3,757,672 dated Sept. 11, 1973 in the names of Robert H. Szabrak and Warren Stubblebine and entitled Deep Fat Fryer Feeding Apparatus, discloses a deep fat fryer of the general type with which the present invention is especially adpated for use although it will be understood that the present invention can also be effectively utilized with other fryer arrangements. The heating unit for heating the hot fat bath in the fryer of the aforementioned patent is of the direct fired type comprising jet burner tubes which direct hot burning gas into heating tubes (FIG. 4 of the patent) running through the bath, for heating the bath to selected temperature.
It is also known in the deep fat fryer prior art to utilize heating units of the indirect heating type which are radiator-type units submerged in the deep fat bath of the fryer and embodying a plurality of tubing loops which carry hot, pressurized, circulating heating liquid or fluid therethrough which may be heated at a source remote from the fryer, for raising the heater units to a predetermined temperature and thus heating the deep fat bath of the fryer to the selected temperature for cooking the food products passed therethrough by the conveyor mechanism of the fryer.
The conveyor mechanism on the fryer comprises the parts thereof which require the most maintenance and repair, although the heating units likewise sometimes require repair, and if the heating units are raised above the bath while at their usual temperature of 500.degree.-600.degree. F., the hot fat bath is very likely to burst into flame, resulting in a fire in the fryer. Accordingly, in the past, it has generally been necessary to permit the heating units to cool down to a predetermined lower temperature before attempting to raise them out of the fryer bath, in order to prevent the likelihood of starting the bath on fire.